Re: Protected Objects: Scoping problem.

[Stephen Leake <Stephen.Leake@gsfc.nasa.gov>]

Robert Worne <rworne@primenet.com> writes:

> I am having a problem with scoping on protected objects.
> 
> I am working on a package that has a protected object that
> communicates to other packages via a "read".  A "write" in that object 
> should be visible only as an internal subprogram, and not visible to the
> outside world.  A simplified version from the Ada documents on-line is:
> 
> package Protected_Variable is
> 
> type T is new integer;
>     
>    protected Variable is
>    function Read return T;
>    procedure Write(Value: T);  -- I do NOT want this accessible to outside
>                                -- packages!
> private
>    Data: T;
> end Variable;
> end Protected_Variable;

That's precisely what the private part of the protected type is for.
Just declare Write in the private part:

package Protected_Variable is
   
   type T is new integer;
   
   protected Variable is
      function Read return T;

   private
      procedure Write(Value: T);  -- NOT accessible to outside packages
      Data: T;
   end Variable;
end Protected_Variable;

<snip> 

-- Stephe